The combination of coagulation, acid cracking and Fenton-like processes for olive oil mill wastewater treatment: phytotoxicity reduction and biodegradability augmentation

Abstract

Olive oil mill wastewater (OOMW) is one of the most important industrial wastewaters in the world due to high organic load and phenolic compounds. In this study, an integration of three processes including coagulation, acid cracking and Fenton-like was evaluated to treat OOMW. The performance of alum, ferric chloride and polyaluminum chloride was studied as coagulants. Among coagulants, ferric chloride showed the best results in comparison with the others. Coagulation process with FeCl3 removed 91.2% chemical oxygen demand (COD), 91.3% phenol, 98.9% total suspended solids and 99.2% turbidity at condition of pH = 6 and 3,000 mg/L coagulant dosage. Acid cracking process following the coagulation process with ferric chloride could slightly degrade organic compounds and provided suitable condition for the next process. Fenton-like process with zero valent iron (ZVI) was applied after coagulation and acid cracking. The optimal removal efficiency was achieved by Fenton-like process which was accomplished in condition of 7 g/L ZVI, 1,000 mg/L H2O2 and 180 min reaction time. The biodegradability of final effluent of this integration was improved significantly and biochemical oxygen demand5/COD value increased from 0.14 to 0.83. The results of germination tests revealed that phytotoxicity of the final effluent decreased.

Chemical Coagulation/Flocculation Processes for Removal of Phenolic Compounds from Olive Mill Wastewater: A Comprehensive Review

“…It passed from charge neutralizationprecipitation mechanism to adsorption mechanism. These results were in agreement with Yazdanbakhsh et al (2015). In the same line, regarding the removal mechanisms of Al-based coagulants, Gregory and Duan (2001) reported that the positively-charged hydroxide precipitates act as destabilizing agents of organic compounds.…”

“…The majority of the tested flocculants completely removed the TSS and reduced considerably the COD and the BOD 5 . In another study, combination of coagulation, acid cracking and Fentonlike process could result the phytotoxicity of final OMW to decrease (Yazdanbakhsh et al, 2015). Stoller and Chianese (2006a) proposed a treatment process comprising an initial coagulation flocculation with aluminium sulphate or aluminium hydroxide, followed by batch UF and NF in series with composite thin film spiral-wound membranes.…”

“…In this context, many research studies have proved that the real treatment of OMW by coagulation cannot been achieved without combinations of existing technologies such as, advanced oxidation processes (Ginos et al, 2006;Rizzo et al, 2008;Amaral-Silva et al, 2016), aerobic biological treatment (Jaouani et al, 2005;Pelendridou et al, 2014;Chiavola et al, 2010), Fenton processes (Rizzo et al, 2008;Lucas and Peres, 2009;Yazdanbakhsh et al, 2015;Madani et al, 2015;Gursoy-Haksevenler, Arslan-Alaton, 2014;Michael et al, 2014;Alver et al, 2015;Ioannou-Ttofa et al, 2017), catalytic ozonation (Eren et al, 2015) and membrane processes (Stoller and Chianese, 2006b;2007;Stoller, 2009).…”

Application of Advanced Oxidation Processes for the Treatment of Recalcitrant Agro-Industrial Wastewater: A Review

“…Studies with combination of two chemical processes were also tested in some works, particularly using coagulation-flocculation and/or acid cracking prior to different Fenton process. Michael et al [6] achieved a high COD removal (87%), while the polyphenolic fraction was eliminated using a solar photo-Fenton; Papaphilippou et al [42] used a UV lamp photo-Fenton and reduced COD and TP by 73% and 87%, respectively; Kiril Mert et al [48] obtained COD reduction of 93% and 95% to TP with Fenton reagent; Kilic et al, [44] achieved almost completely degradation of TOC, COD, and TP (99%); and Yazdanbakhsh et al, [51] achieved 98% of TP removal, improving biodegradability (biochemical oxygen demand (BOD 5 /COD ratio) from 0.14 to 0.83. This combination of processes may constitute a potential solution for purification of OMW.…”

Performance of Advanced Oxidization UV/S2O8-2 in Removing Acid Green 3 from Aqueous Solutions: Modeling Based Linear Regression, Kinetic Studies

“…It has been proven that advanced oxidation processes (AOPs) are a good choice for treating wastewaters which cannot be easily treated using biological processes. The basis of treatment in AOP processes is the production of active radicals such as hydroxyl radical (OH • ) (6). Photochemical processes are a branch of AOPs in which UV radiation activates chemical compounds to generate OH • radicals.…”